Minimal clinically important change in Abnormal Involuntary Movement Scale score in tardive dyskinesia as assessed in pivotal trials of deutetrabenazine

Bridging the gap between statistical significance and clinical relevance: A systematic review of minimum clinically important difference (MCID) thresholds of scales reported in movement disorders research

“… Author, Year No. of patients Mean Age Disease (specific treatment) Disease Duration in years Age at disease onset (years) Disease Severity, n(%) or points (Mean ± SD) Time from disease onset to diagnosis, years Time from diagnosis to treatment, years Major Treatment received 23 Krismer et al, 2016 [ 11 ] 174 65 (8.5) MSA-P (Rasagiline) Placebo - 3.7 ± 2.4 Rasagiline - 4.2 ± 2.4 Total UMSARS; Placebo - 36.4 ± 9.1, Rasagiline – 38.1 ± 8.6 – – Rasagiline 24 Hewer et al, 2016 [ 12 ] 313 68 (6.6) PSP (Duvanetide) PSPRS - Levodopa use – 131 (42%) 25 Hauser et al, 2022 [ 18 ] 256 56.8 (10.19) Tardive Dyskinesia 5.8 ± 6.01 – 9.9 ± 3.0 – – 26 Barkey et al, 2021 [ 23 ] 295 – Tardive dyskinesia (Deutetrabenazine) – – – – – Deutetrabenazine 27 Stacy et al, 2019 [ 10 ] 373 – Tardive dyskinesia (Valbenazine) …”

“… MFIS total, MFIS cognitive, and MFIS physical Yes x Yes x 13.8, 6.8 and 6.2 for the MFIS total, MFIS cognitive, and MFIS physical, respectively. 23 Krismer et al, 2016 [ 11 ] MSA-P (Rasagiline) UMSARS Total, ADL, Motor x Yes Yes x UMSARS: Total worsening 3.5 ADL subscale worsening 1.5 Motor examination subscale worsening 1.5 24 Hewer et al, 2016 [ 12 ] PSP (Duvanetide) PSPRS x x Yes Yes x Worsening 5.7 points 25 Hauser et al, 2022 [ 18 ] Tardive Dyskinesia Abnormal Involuntary Movement Scale (AIMS) x Yes x Yes x −2 points 26 Barkey et al, 2021 [ 23 ] Tardive dyskinesia (Deutetrabenazine) Abnormal Involuntary Movement Scale (AIMS) x x Yes Yes x 3 27 Stacy et al, 2019 [ 10 ] Tardive dyskinesia (Valbenazine) Abnormal Involuntary Movement Scale (AIMS) x x Yes Yes …”

Scales for Antipsychotic‐Associated Movement Disorders: Systematic Review, Critique, and Recommendations

“…Finally, it has not been clearly validated to rate patients' video recordings, although a minimal clinically important difference of two points was estimated through video assessments. 35,36 Our judgment of uncertainty related to the application to acute movement disorders of instruments originally developed for tardive movement disorders stems from phenomenological differences between acute dystonia and akathisia and their tardive counterparts. 10,13 Also, antipsychotic-associated parkinsonism cannot be easily subdivided into acute, subacute, or chronic types, and the attribute of tardive is, albeit with some exceptions, 28 usually discouraged for parkinsonism.…”

“…Moreover, the AIMS is skewed toward facial movements, 17 and raters are instructed to ignore the presence of tremor; however, this remains the most commonly deployed instrument in clinical trials or observational studies to measure antipsychotic‐associated hyperkinetic movements that are not akathisia. Finally, it has not been clearly validated to rate patients' video recordings, although a minimal clinically important difference of two points was estimated through video assessments 35,36 …”

“…Among the most widely used scales, the AIMS for hyperkinetic movements and the SAS for parkinsonism fulfill this ideal scenario. For the AIMS, a minimal clinically relevant change of two points has been identified, 35,36 making this scale the most suitable to measure change in hyperkinetic disorders. Insufficient knowledge of responsiveness to change may also explain why some clinical trials resorted to rating scales developed to assess non-drug-induced movement disorders (eg, the Burke-Fahn-Marsden scale for dystonia 39 or the Unified Parkinson's Disease Rating Scale for parkinsonism 40 ), although none of these generic scales were validated for antipsychotic-associated movement disorders.…”